1. Technical Field
The present disclosure relates to a production method of a sintered alloy, a sintered-alloy compact, and a sintered alloy.
2. Description of Related Art
A sintered alloy containing iron as the base may be applied to a valve seat or the like of an internal combustion engine. In order to further improve wear resistance, hard particles may be included in a sintered alloy. In a case where hard particles are included, graphite particles and iron particles are mixed with the hard particles into a powder, and the mixed powder is compacted into a sintered-alloy compact. Thereafter, by heating the sintered-alloy compact and sintering the resultant, a sintered alloy is generally obtained.
As a production method of such a sintered alloy, a production method of a wear-resistant iron-based sintered alloy, in which mixed powder obtained by mixing hard particles, graphite particles, and iron particles together is compacted into a sintered-alloy compact, and the sintered-alloy compact is sintered while causing carbon (C) of the graphite particles of the sintered-alloy compact to diffuse into the hard particles and the iron particles, is suggested (for example, refer to Japanese Patent Application Publication No. 2004-156101 (JP 2004-156101 A)).
Here, the hard particles contains 20 to 70 mass % of Mo, C: 0.2 to 3 mass %, Mn: 1 to 15 mass %, and the remainder including unavoidable impurities and Co, and the mixed powder contains, when the total amount of the hard particles, the graphite particles, and the iron particles is assumed to be 100 mass %, 10 to 60 mass % of the hard particles and 0.2 to 2 mass % of the graphite particles. Since the hard particles are dispersed in the sintered alloy, abrasive wear can be suppressed.